{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42486","assignerOrgId":"23aa2041-22e1-471f-9209-9b7396fa234f","state":"PUBLISHED","assignerShortName":"XEN","dateReserved":"2026-04-27T14:20:24.138Z","datePublished":"2026-07-09T15:16:34.880Z","dateUpdated":"2026-07-09T16:16:34.894Z"},"containers":{"cna":{"providerMetadata":{"orgId":"23aa2041-22e1-471f-9209-9b7396fa234f","shortName":"XEN","dateUpdated":"2026-07-09T15:16:34.880Z"},"title":"Multiple RBAC issues in XAPI","datePublic":"2026-04-28T18:05:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-250","description":"CWE-250 Execution with unnecessary privileges","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-233","descriptions":[{"lang":"en","value":"CAPEC-233 Privilege Escalation"}]}],"affected":[{"vendor":"Xen","product":"XAPI","versions":[{"status":"affected","version":"all"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]\nXAPI can configure different users with different roles, using Role\nBased Access Control. For more details, see:\n\n https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles\n\nThe pool-admin role is fully privileged. Notably, users with this role\ncan also SSH into the host as root.\n\nThe other administrator roles are pool-operator, vm-power-admin and\nvm-admin, each of which are authorised to configure and manage various\naspects of the system.\n\nSome settings are inadequately restricted, and can be set by a lower\nprivilege of administrator than expected.\n\n * CVE-2026-23559: A vm-admin can set VBD.other_config:backend-local and\n turn arbitrary files in dom0 into VDIs (virtual disks) and give said\n disks to a VM they control. This is an arbitrary read and/or modify\n of files in dom0.\n\n * CVE-2026-23560: A vm-admin can set VM.other-config:is_system_domain\n and mark a VM as a system domain. System domains are ignored and\n left running during certain other host/pool operations, and may be\n hidden from view in tooling.\n\n * CVE-2026-23561: A vm-admin can set VM.other_config:storage_driver_domain\n and mark a VM as the storage domain for a particular host storage\n connection (PBD). Shutting down the VM can cause the PBD to be\n erroneously marked as unplugged when it is not.\n\n * CVE-2026-23562: Configuration of PCI passthrough is normally\n restricted to the pool-admin role. However one API was missing this\n check, allowing a vm-admin access to unintended host hardware.\n\n * CVE-2026-42486: A vm-admin can set the VM.platform:hvm_serial\n parameter, which should be restricted to the pool-admin role, as it\n can allow arbitrary dom0 file write.","supportingMedia":[{"type":"text/html","base64":false,"value":"[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]
XAPI can configure different users with different roles, using Role
Based Access Control. For more details, see:

https://docs.xenserver.com/en-us/xencenter/current-release/rbac-overview.html#rbac-roles

The pool-admin role is fully privileged. Notably, users with this role
can also SSH into the host as root.

The other administrator roles are pool-operator, vm-power-admin and
vm-admin, each of which are authorised to configure and manage various
aspects of the system.

Some settings are inadequately restricted, and can be set by a lower
privilege of administrator than expected.

* CVE-2026-23559: A vm-admin can set VBD.other_config:backend-local and
turn arbitrary files in dom0 into VDIs (virtual disks) and give said
disks to a VM they control. This is an arbitrary read and/or modify
of files in dom0.

* CVE-2026-23560: A vm-admin can set VM.other-config:is_system_domain
and mark a VM as a system domain. System domains are ignored and
left running during certain other host/pool operations, and may be
hidden from view in tooling.

* CVE-2026-23561: A vm-admin can set VM.other_config:storage_driver_domain
and mark a VM as the storage domain for a particular host storage
connection (PBD). Shutting down the VM can cause the PBD to be
erroneously marked as unplugged when it is not.

* CVE-2026-23562: Configuration of PCI passthrough is normally
restricted to the pool-admin role. However one API was missing this
check, allowing a vm-admin access to unintended host hardware.

* CVE-2026-42486: A vm-admin can set the VM.platform:hvm_serial
parameter, which should be restricted to the pool-admin role, as it
can allow arbitrary dom0 file write."}]}],"references":[{"url":"https://xenbits.xen.org/xsa/advisory-489.html"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"CRITICAL","baseScore":9.4,"vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T16:16:29.894886Z","id":"CVE-2026-42486","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-09T16:16:34.894Z"}}]}}